Elements in the same family have similar properties because they share the same number and distribution of valence electrons, leading to similar chemical behaviors. Group patterns like the alkali metals in Group 1A with one valence electron contribute to these predictable reactivity patterns. Trends, such as increasing metallic character down a group, are also observed.
Elements in the same family or group of the periodic table generally have similar properties because they have the same number and distribution of electrons in their valence shells. This similarity in electron configuration explains their comparable chemical behaviors. For instance, all elements in Group 1A have one valence electron, which leads to common reactivity patterns and they are known as the alkali metals. As we progress along a group, there are also trends, such as an increase in metallic character from nonmetals like oxygen to metals like polonium.
In the 19th century discoveries, similar compounds formed by the reactions of elements such as lithium, sodium, and potassium with other elements underscored the pattern of similar chemical properties within a group. The figure from the provided reference indicates that within a group, elements have the same s and p valence electron configurations, which play a crucial role in their reactions and interactions.
Therefore, the periodic table is deliberately structured to group elements with similar properties, following the patterns of electron configurations, specifically within their valence shells, resulting in the elements' predictable chemical behavior. This order mirrors the sequential filling of electron subshells, ensuring that elements in a family react similarly in chemical reactions.
List at least two chemical reactions that resulted in the yellow orange or red preList at least two chemical reactions that resulted in the yellow orange or red precipitate. For these reactions list the possible chemical name of the precipitate. What do these reactions (and other similar to them) have in common?
Answer:
2,4-dinitrophenylhydrazine (Brady’s reagent)
Explanation:
how can you increase friction
Answer:Well There is many ways to increase friction between objects. One being rubbing the two objects together quicker and harder. If there is any sort of wetness or anything related to that make sure to dry the surface between the two objects you want to create friction between so it will be more effective.
Explanation:
For the reaction, 2A + B → 3C, rate of disappearance of A is 0.3 M/s in a certain time interval.What is the average rate of appearance of C and what is the average rate of the reaction in that time interval?
A) rate of appearance of C = 0.45 M/s
rate of the reaction = 0.6 M/s
B) rate of appearance of C = 0.2 M/s
rate of the reaction = 0.6 M/s
C) rate of appearance of C = 0.2 M/s
rate of the reaction = 0.15 M/s
D) rate of appearance of C = 0.45 M/s
rate of the reaction = 0.3 M/s
E) rate of appearance of C = 0.45 M/s
rate of the reaction = 0.15 M/s
Answer:
E) rate of appearance of C = 0.45 M/s
rate of the reaction = 0.15 M/s
Explanation:
2A + B → 3C
Writing rate law for the reaction:
Rate of reaction = -[tex]\frac{1}{2}[/tex][tex]\frac{d[A]}{dt}[/tex] = -[tex]\frac{d[B]}{dt}[/tex] = [tex]\frac{1}{3}[/tex][tex]\frac{d[C]}{dt}[/tex] → equation 1
Given that the rate of disappearance of A is 0.3 M/s
⇒ - [tex]\frac{d[A]}{dt}[/tex] = 0.3 M/s
⇒Rate of reaction = - [tex]\frac{1}{2}[/tex][tex]\frac{d[A]}{dt}[/tex] = [tex]\frac{1}{2}[/tex]×0.3 M/s
⇒Rate of reaction = 0.15 M/s
From equation 1, [tex]\frac{d[C]}{dt}[/tex] = - [tex]\frac{3}{2}[/tex][tex]\frac{d[A]}{dt}[/tex] = [tex]\frac{3}{2}[/tex]×0.3 M/s
⇒[tex]\frac{d[C]}{dt}[/tex] = 0.45 M/s
or the rate of appearance of C = 0.45 M/s
I need help with a science packet about newtons second law !!
Answer:
The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
What is the mass of neon that exerts a pressure of 720. mmHg, with a temperature of -15.0 °C , when the volume of the container is 760. mL?
Final answer:
To find the mass of neon, we can use the ideal gas law and calculate the number of moles of neon first.
Explanation:
To solve this problem, we can use the ideal gas law, which states that PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
P: Pressure = 720 mmHg
T: Temperature = -15.0 °C (convert to Kelvin: 258.15 K)
V: Volume = 760 mL (convert to m³: 760 * 10⁻³ m³)
n: Number of moles of neon (unknown)
m: Mass of neon (unknown)
R: Ideal gas constant = 8.314 J/mol·K
2. Apply the ideal gas law:
The ideal gas law relates pressure, volume, temperature, and the number of moles of a gas:
PV = nRT
3. Rearrange the equation to solve for n:
n = PV / RT
4. Substitute the known values and calculate n:
n = (720 * 133.3224 Pa) * (760 * 10⁻³ m³) / (8.314 J/mol·K * 258.15 K)
Convert mmHg to Pa using the conversion factor 1 mmHg = 133.3224 Pa.
n ≈ 0.0340 mol
5. Calculate the mass of neon:
m = n * M
where M is the molar mass of neon (20.18 g/mol).
m = 0.0340 mol * 20.18 g/mol
m ≈ 0.686 g
Therefore, the mass of neon in the container is approximately 0.686 grams.
You have decided to do an experiment to learn if a certain type of cactus will grow better in a dark closet or a sunny window. To begin your experiment, you place one cactus in a dark closet and one cactus in a sunny window. Over the next month, you record data about the cacti and their appearance every day. At the end of the month, you determine that the cactus in the sun is alive but didn’t grow and that the cactus from the dark closet is alive and grew one centimeter. Can you conclude that a dark closet is better for this type of cacti’s growth?
A.
No, you need to repeat an experiment multiple times before accepting a conclusion.
B.
No, you need to use one cactus in both conditions.
C.
Yes, when you are a student your results will be accepted on small-scale studies.
D.
Yes, one cactus can accurately reflect the behavior of all similar cacti.
Answer: No, you need to repeat an experiment multiple times before accepting a conclusion.
Answer: A. No, you need to repeat the experiment multiple times before accepting a conclusion.
What temperature, pressure, and water vapor concentration would you expect to see in the
Stratopause?
The expected parameters in Stratopause are; Temperature: -15 degrees Celsius, Pressure: 1 milibar and Water vapor concentration: cannot be determined.
Explanation:
"Stratopause" is the interaction between the ionosphere and the stratosphere. It is 50-55 km high above the earth surface that is why temperature is very less approximately -15 degrees Celsius (5 degrees Fahrenheit). As it is a thin layer separating the stratosphere and ionosphere actual water vapor concentration cannot be determined. The atmospheric pressure is around 1/1000 of the pressure at sea level.
Final answer:
The stratopause, located at about 50 km above Earth, has a constant temperature close to 0°C, low pressure, and very low water vapor concentration due to the absence of conditions that support water in other phases.
Explanation:
In the stratopause, which is the boundary layer between the stratosphere and the mesosphere located approximately 50 kilometers above the Earth's surface, one could expect to see a fairly constant temperature sufficing approximately at 0°C or 273.16 K. The temperature increases slightly in the stratosphere because it is heated from below by the absorption of ultraviolet radiation by ozone.
The pressure and density are much lower than at the Earth's surface due to the height in the atmosphere, and because the temperature is constant, pressure and density decrease together as altitude increases. In the stratosphere, there is almost no water vapor, much less than in the troposphere, so the concentration of water vapor in the stratopause would be very low. This is because the atmosphere's temperature at this layer does not support the presence of much water vapor, which would predominantly be in gaseous form if present.
53)
The mass of a calcium atom is due primarily to the mass of its
A) protons, only
B)neutrons, only
C)protons and neutrons
D) protons and electrons
A radar gun records the speed of a projectile to be 120.090 m/s. How many significant digits are present in this measurement?
The measurement of 120.090 m/s recorded by the radar gun contains six significant digits, with all digits being significant.
In physics, understanding the concept of significant figures is essential for accurately reporting the measurements we make. The speed of a projectile recorded by a radar gun as 120.090 m/s contains six significant digits. This is because all non-zero numbers are always significant, any zeros between non-zero numbers are significant, and any trailing zeros to the right of the decimal point are also significant. Therefore, each digit in the measurement, 1, 2, 0, 0, 9 and 0, are all significant, giving us a total of six significant figures in the speed of the projectile.
The number of significant digits in a measurement is determined by the certainty of the measuring device.
In the given speed measurement of 120.090 m/s, there are five significant digits because each non-zero digit is significant, the trailing zero after the decimal point counts, and any zero between significant digits is also counted.
In this case, the significant digits are 120.090.
What is the final volume of NaOH solution prepared from 100.0 mL of 0.500 M NaOH if you wanted the final concentration to be 0.150 M?
Answer:
The final volume of NaOH solution is 30ml
Explanation:
We all know that
V1S1 = V2S2
or V1= V2S2÷S1
or V1= V2×S2×1/S1
or V1=100×0.15×1/0.50
V1= 30
∴30 ml NaOH solution is required to prepare 0.15 M from 100ml 0.50 M NaOH solution.
The final volume of the NaOH solution, with the desired concentration of 0.150 M, can be calculated using the concept of molarity. Plugging the initial molarity, volume, and final molarity into the formula M1V1 = M2V2 gives a final volume of approximately 333.3 mL.
Explanation:To calculate the final volume of the NaOH solution, we will use the concept of molarity, which is represented by the equation M1V1 = M2V2 where M1 and V1 are the initial molarity and volume, and M2 and V2 are the final molarity and volume. In the given problem, the initial molarity (M1) is 0.500 M, the initial volume (V1) is 100 mL, and the desired final molarity (M2) is 0.150 M.
Accordingly, we rearrange the equation to solve for V2: V2 = (M1V1) / M2. Substituting the given values, we find V2 = (0.500 M × 100 mL) / 0.150 M = 333.3 mL.
So, you would need to dilute the initial 100 mL of 0.500 M NaOH solution to a final volume of approximately 333.3 mL to achieve a final concentration of 0.150 M.
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Perform the following operation and express the answer in scientific notation. 7.0x10^3x1.1x10^7
Answer:
The answer is: [tex]7.7\times10^{10}[/tex]
Explanation:
Scientific notation is of the kind: [tex]a.bc\times10^{x}[/tex]
The given calculation:
[tex]7.0\times10^{3}\times1.1\times10^{7}=(7\times1.1)\times10^{(3+7)}[/tex]
[tex]=7.7\times10^{10}[/tex]
Therefore, the answer in scientific notation is: [tex]7.7\times10^{10}[/tex]
_Pb304 + _HNO3 → __Pb(NO3)2 + __PbO2 + __H2O
Pb₃O₄ + 4HNO₃ → 2Pb(NO₃)₂ + PbO₂ + 2H₂O
Explanation:Balancing a chemical equation involves putting appropriate coefficients on the reactants and products to make the number of atoms of each element involved equal on both sides of the equation.When a chemical equation is balanced then it obeys the law of conservation of mass.The law of conservation of mass requires the mass of reactants to be equal to the mass of the products.In this case, to balance the equation, we put the coefficients 1, 4, 2, 1 and 2 receptively on the equation.Thus, the balanced equation will be;
Pb₃O₄ + 4HNO₃ → 2Pb(NO₃)₂ + PbO₂ + 2H₂O\
Therefore, on the reactants side there are 3 Pb atoms, 16 O atoms, 4 H atoms and 4 nitrogen atoms.Product side : 3 Pb atoms, 16 O atoms, 4 H atoms and 4 nitrogen atoms.Thus, the equation obeys the law of conservation of mass.
QUESTION 1
Which of these quantities determines the amount of heat released when freezing a given amount of a substance?
specific heat capacity
thermal energy
latent heat of fusion
latent heat of vaporization
QUESTION 2
The enthalpy of freezing for water is −6.02 kJ/mol. What does this indicate?
No heat transfer occurs.
Heat is absorbed.
Heat is released.
The process is endothermic.
QUESTION 3
What does a positive value for enthalpy of vaporization indicate?
The process is endothermic.
The process is exothermic.
No heat transfer occurs.
Heat is released by the liquid.
Answer:
The answers are:
1) Latent heat of fusion
2) Heat is released
3) The process is endothermic
Explanation:
(1) The amount of energy required to freeze one kg of a substance is called latent heat of fusion.
(2) In a process, if heat is absorbed, the change in enthalpy for the substance is positive.
In a process, if heat is released, the change in enthalpy for the substance is negative.
The enthalpy of freezing for water is -6.02 kJ/mol. Heat is released as the enthalpy is negative.
(3) A positive value for enthalpy of vaporization indicates that the process is endothermic.
An exothermic process is one in which energy is released. The enthalpy for the process is negative.
An endothermic process is one which energy is absorbed. The enthalpy for the process is positive.
Which sample or gas would you exert the greatest pressure, assuming that the volume of each sample is the same?
A) one mole of N2 at 100 K
B) one mole of H2 at 250 K
C) one mole of O2 at 175 K
D) one mole of CO2 at 330 K
D
Because the moles of the gases are the same,and the volume too, the gas with the highest temperature will exert the highest outward pressure to its environment. It, therefore, will require an equivalent pressure exerted on the gas to maintain its volume.
Explanation:
According to ideal gas laws, pressure, volume, and temperatures of gases are related in a formula;
PV/T = C
Whereby
P = Pressure
V = Volume
T= Temperatures
C = Constant
To understand how much pressure a gas exerts with change in temperature, while volume remains the same, we can evaluate the formulae in this way;
P = T/V
Therefore an increase in temperature, while volume is the same, means the Pressure will rise.
Learn More:
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Answer:
its right
Explanation:
The controlled Release of nuclear energy in a creator is accomplished by: allowing the critical mass of fuel to react . Controlling a chain reaction. Controlling fission without a chain reaction. All of the above.
Answer:
If a chain reaction takes place, the amount of energy released would increase exponentially, so in order to control the energy release, fission must be controlled without controlling a chain reaction, so the third option is correct.
Hope this helps!
Explanation:
PLEASE HELP ASAP Why does a liquid’s rate of evaporation increase when the liquid is heated? A. The potential energy of the liquid increases. B. The surface area of the liquid is reduced. C. The average kinetic energy of the liquid decreases as the temperature of the liquid increases. D. More molecules have enough energy to overcome the attractive forces holding them in the liquid.
Answer:
D
Explanation:
Answer:
A. More molecules have enough energy to overcome the attractive forces holding them in the liquid.
Explanation:
the wave mechanical model of the atom is required to explain the
The wave mechanical model of the atom represents electrons as waveforms existing within regions (electrons clouds or orbitals) where they have a probability of being found, rather than precise orbits. It also explains electron energy levels and how electrons change energy states.
Explanation:The wave mechanical model of the atom, also known as the quantum mechanical model, is primarily required to explain the behavior of electrons within an atom. Unlike the more simplistic Bohr model, which treats electrons as particles moving in precise orbits, the wave mechanical model treats electrons as waveforms.
This model more accurately reflects how electrons do not have precise locations within an atom, but rather exist within areas called electron clouds or orbitals, where they have a higher probability of being found. These orbitals are the regions in an atom where electrons are likely to be found and can be visualized as fuzzy clouds surrounding the nucleus.
For instance, in the base state, electrons reside in the lowest possible energy level, or ground state. If energy is provided to the atom, such as through heat or light, electrons can move to a higher energy level, known as an excited state. When the electron returns to the ground state, it releases energy, often as light.
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The wave mechanical model of the atom allows for the probabilistic description of atomic structure, particularly the behavior of electrons. This model explains that electrons exhibit wave-particle duality and exist in an electron cloud around the nucleus. It is essential to understand chemical bonding, electron configuration, and atomic spectra.
Explanation:The wave mechanical model, or quantum model, of the atom, is fundamental in explaining the behaviors and characteristics of atoms, particularly the behavior of electrons. This model grew from the work of de Broglie and Heisenberg. De Broglie proposed that particles such as electrons can also have properties of waves - an idea known as wave-particle duality.
Building on this, Heisenberg introduced the uncertainty principle, asserting that it's impossible to precisely determine both the position and momentum of a particle at the same time. This led to the concept of an electron cloud, which is a probabilistic model of where an electron is likely to be at any given time. Schrödinger further expanded this with his wave equation, which could calculate the probable locations of electrons, these calculations are termed wavefunctions or orbitals.
Therefore, the quantum mechanical model illustrates the atom not as a mini solar system with well-defined orbits, but in terms of probability distributions with various shapes and orientations around the nucleus where the electron could be found. This model is required to describe atomic properties such as electron configuration, atomic spectra, and chemical bonding.
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The graph below is an age structure diagram for a population of Africa elephants
According to the diagram in which age classes do females out number males
Answer:
Option A) C, E and F
Explanation:
It is very clear from the graph, that females will outnumber males in the particular age category where the orange occupies a greater number.
Therefore through observation, we can see that the orange color which denotes females is greater than blue color which denotes males in the following age categories-
Category C- 20-24.9 years of age,
Category E- 35-49.9 years of age and
Category F- >50 years of age.
Hence, C, E and F only.
An atom has the following electron configuration.
1s22s22p63s23p4s23d3
How many valence electrons does this atom have?
The atom with the given electron configuration, assuming the typo is corrected, has 5 valence electrons, which are the electrons from the 4s and 3d sublevels.
Explanation:Valence electrons are the electrons in the outermost energy level of an atom and are involved in chemical bonding. According to the given electron configuration 1s22s22p63s23p4s23d3, we need to identify the outermost electrons. The configuration actually seems to contain an error as '3p4s23d3' is not a standard notation, but assuming the correct sequence and based on the highest principal quantum number, the valence electrons would be from the 4s sublevel (2 electrons) and the 3d sublevel (3 electrons), adding up to 5 valence electrons.
determine the h+ of 0.005 KOH
Answer:
[H⁺] = 2.0 × 10⁻¹² M
Explanation:
Given data:
Concentration of KOH = 0.005M
H⁺ = ?
Solution:
pOH = -log[ OH⁻]
pOH = -log[0.005]
pOH = 2.3
pH + pOH = 14
14 - pOH = pH
pH = 14 - 2.3
pH = 11.7
pH = -log[H⁺]
11.7 = -log[H⁺]
[H⁺] = Antilog (-11.7)
[H⁺] = 2.0 × 10⁻¹² M
2. What ions are present in what ratio in a solution of aqueous calcium chloride?
a. Ca2+(aq) + Cl22-(aq)
b. Ca2+ (aq) + Cl2 (aq)
Final answer:
In a solution of aqueous calcium chloride, there are two Cl- ions for every Ca2+ ion.
Explanation:
The proper ionic formula for aqueous calcium chloride is CaCl2. This means that in a solution of aqueous calcium chloride, there are two Cl- ions for every Ca2+ ion.
In a solution of aqueous calcium chloride (CaCl₂), the ions present are (a) Ca²⁺ and Cl⁻ in a 1:2 ratio.
A solution of aqueous calcium chloride (CaCl₂) dissociates into its constituent ions in water. The dissolution equation is as follows:
CaCl₂(s) → Ca²⁺(aq) + 2Cl⁻(aq)
This means that for every 1 molecule of CaCl₂ that dissolves, it produces 1 calcium ion (Ca²⁺) and 2 chloride ions (Cl⁻). Therefore, the ions are present in a 1:2 ratio in the solution.
Complete Question - 2. What ions are present in what ratio in a solution of aqueous calcium chloride?
a. Ca²⁺(aq) and Cl⁻(aq)
b. Ca²⁺ (aq) + Cl₂ (aq)
Maximum number of possible structural of C7H9N
There are 5 possible structural isomers with the molecular formula C₇H₉N.
Explanation:
You may find the chemical diagrams of the structural isomers in the attached picture.
Learn more about:
structural isomers
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A car tyre has a pressure of 2.6 atm at 10°C. If the pressure inside
reaches 5 atm, the tyre will fail. How hot would the tyre have to get for
this to happen?
Answer:
T = 271.23 degree celcius
Explanation:
For the gas inside the tyre
PV = nRT
So, P is directly proportional to T.
[tex]\frac{P_{1} }{P_{2} }[/tex] = [tex]\frac{T_{1} }{T_{2} }[/tex]
[tex]\frac{2.6}{5}[/tex] = [tex]\frac{283}{T}[/tex]
T = 544.23 K = 271.23 degree celcius
So, Tyre have to get the temperature 271.23 degree celcius for this to happen.
What does it mean for a hypothesis to be testable?
A. The hypothesis must be what the scientist is hoping is the result.
O
B. The hypothesis must be able to be proved true or false.
O
C. The hypothesis must be supported by peer review.
O
D. The hypothesis must be able to reject biased data.
Answer:
Option B
Explanation:
The hypothesis needs to produce results that can prove it to be true or false.
A testable hypothesis in science can be experimented or observed to determine its truth or falsehood.
Explanation:A testable hypothesis in science means that it can be tested through experimentation or observation to determine if it is true or false. This is an essential aspect of the scientific method, which aims to gather empirical evidence to support or reject hypotheses. In order for a hypothesis to be testable, it must be formulated in a way that allows for the collection of evidence that can support or refute it.
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What is the concentration (M) of a NaCl solution prepared by dissolving 9.3 g of NaCl in sufficient
water to give 350 mL of solution?
Answer:
Molarity = 0.458M
Explanation:
Molarity is the representation of the solution.
Molarity:
it is amount of solute in moles per litre of solution and represented by M
Formula used for Molarity
M = moles of solute / Litre of solution
Data Given:
NaCl = 9.3 g
volume of solution = 350 mL
volume of solution in litre = 350/1000
volume of solution = 0.35 L
Molarity = ?
Formula used to Calculate M
M = moles of NaCl / Litre of solution . . . . . . . . . (1)
So
we have to first calculate moles of NaCl
Moles of NaCl = mass of NaCl/ Molar Mass (NaCl) . . . . . . . (2)
*Molar Mass of NaCl = 58 g/mol
Put values in Eq (2)
Moles of NaCl = 9.3 g/ 58 g/mol
Moles of NaCl = 0.16 mol
Now
Put values in Eq (1)
M = 0.16 mol / 0.35 L
M = 0.458
So the Molarity = 0.458M
Taking into account the definition of molarity, the concentration (M) of the NaCl solution is 0.45 [tex]\frac{moles}{liter}[/tex].
It is necessary to know that molarity reflects the concentration of a solution, indicating the number of moles of solute that appear dissolved in a given volume. In other words, molarity is the amount of a substance in a certain volume of solution.
Molarity is also known as the molar concentration of a solution.
The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:
[tex]molarity=\frac{number of moles of solute}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
In this case, molar mass is the mass of one mole of a substance. Then, the molar mass of NaCl being 58.45 [tex]\frac{g}{mole}[/tex], the number of moles representing 9.3 g of NaCl is calculated as:
[tex]amount of moles=\frac{9.3 g}{58.45 \frac{g}{mole}}[/tex]
amount of moles= 0.159 moles
On the other side, the volume of the solution is 350 mL= 0.350 L (being 1000 mL=1 L)
Replacing in the definition of molarity:
[tex]molarity=\frac{0.159 moles}{0.350 L}[/tex]
Solving:
molarity= 0.45 [tex]\frac{moles}{liter}[/tex]
Finally, the concentration (M) of the NaCl solution is 0.45 [tex]\frac{moles}{liter}[/tex].
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what mass of oxygen combines with 2.00 moles of magnesium
Answer:
32.0 g O2
Explanation:
[tex]2.00 \: mol \: mg \: x \frac{1 \: mol \: o2}{2 \: mol \: mg} x \: \frac{32.0 \: g \: o2}{1 \: mol \: o2} = 32.0 \: g \: o2[/tex]
I'm not sure if I understood your question correctly so your better off not using my answer lol
How do the results of the iodine test indicate that hydrolysis of starch occurred
Answer:
Blue color of iodine-starch complex is disappear upon hysrolysis
Explanation:
Starch:
Starch is a polysaccharide
it is energy reservoir.
starch is made of monomers of glucose in a chain form.
The simplest form of starch is linear polymer amylose.
Iodine Test:
In this test iodine solution added to the solution to check the presence of starch.
Iodine solution = elemental iodine + KI
Result of Iodine Test:
when the iodine solution (I₃⁻) is added to a solution it show two types of result.
if the starch is present this I₃⁻ form a complex with amylose chain of starch and impart a dark blue color.
if starch is not present then the color will be orange or yellow.
Hydrolysis of Starch:
Hydrolysis of starch is carried out by an enzyme, this enzyme break down the starch into simpler sugar molecule.
So,
When the hydrolysis of starch occur the starch convert to glucose. Then the blue color of starch and iodine complex formed during iodine test is disappear that will be the indication of hydrolysis of starch.
The mass percent of a solution made by dissolving 59.1 g of kf in 947 g of h2o
Answer:
5.87%
Explanation:
Mass fraction of a solution is the ratio of mass of the solute to the total mass of the solution (Note that it is the total mass of the solution, i.e the sum of masses of solvent and solute). Mass percent is mass fraction times 100.
Here, the solute is KF and its mass is 59.1g. The solvent as usual is [tex]H_{2}O[/tex] and its mass is 947g. Therefore, the total mass of the solution (solution is the mixture of solvent and solute, here KF and [tex]H_{2}O[/tex]) is 59.1 + 947 = 1006.1g.
The mass fraction is the ratio of mass of KF to the total mass of solution = [tex]\frac{59.1}{1006.1} = 0.0587[/tex].
Thus, the mass percent is mass fraction × 100 = 0.0587 × 100 = 5.87 %
How many moles of are in 179 mL of a 3.0 M of CaCl2 solution?
Answer: 0.537 moles
Explanation:
Hello, Let's first explain the term molarity
---> Molarity is the most commonly used term to describe the concentration of a solution. It is equal to the moles of solute divided by the liters of solution.
---> The solute is defined as the substance being dissolved, while the solvent is the substance where the solute is dissolved (usually water).
---> The solution is the combination of the solute and the solvent.
Molarity = moles of solution/Liters of
solution
Parameters given are
Volume(V) = 179ml of CaCl2 solution
Molarity = 3.0m
Therefore,
Molarity = number of moles of CaCl2 solution / Volume of CaCl2 in Liters (eqn 1)
First, convert 179ml to liters
1ml = 0.001L
179ml = ?
179ml = 179ml x 0.001L
= 0.179L
From (eqn 1)
Let the number of moles of CaCl2 solution be M
=> 3 = M/0.179
M = 0.179 x 3
= 0.537 moles
Hence the number of moles in 179ml of CaCl2 solution yields 0.537 moles
• How do materials move
inside plants?
Answer:
It is a way for water, minerals, and sugars to move between the roots and leaves. Roots, stems, and leaves have two types of vascular tissues: Xylem: brings water and minerals from the roots to the stem and leaves. Phloem: brings sugar that is made in the leaves down to the rest of the plant.